JPH0250479A - Complete contact type actual size image sensor - Google Patents

Abstract

PURPOSE:To satisfactorily convey an original at the time of reading of an original image and to surely hold a sensor on a supporting plate by employing the plate having a groove which satisfies specific relation formulas. CONSTITUTION:A sensor 2 having a photoelectric converter 4 is held on a supporting plate 1 on a light transmissive board 3, and a groove which satisfies relation formulae of 0 deg.<theta<90 deg., tantheta<=t/1 is formed on the plate 1. In the formulae, theta is an angle of the side directed toward a gravity direction perpendicular to the plate 1, t is the depth of an original 5 at the upstream side of a conveying direction of the original 5', t' is similarly the depth at the downstream side, and 1 is width. The sensor 2 having thickness d (where d<=t) is engaged with the groove to be held. Thus, the original can be satisfactorily conveyed at the time of reading of original image, and the sensor can be surely held on the plate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fully contact type 1-magnification image sensor used in facsimiles and the like.

[Prior art]

A fully contact type 1x image sensor that reads the original image by placing the original and the sensor unit in close contact with each other without using a 1x imaging system has higher resolution than one using a 1x imaging system, and It has the advantage of being inexpensive. As shown in FIG. 2, this type of complete contact type image sensor is basically constructed by holding a sensor section 2 having a photoelectric conversion element 4 on a transparent substrate 3 on a support plate 1. There is (Special Public Service 1977)
-44470, 5g-14073, JP-A-58-
127463, etc.), but in the case where the sensor part 2 is simply adhesively held on the support plate 1 as shown in FIG. ~ Not being conveyed well between backup rollers 6,
This may cause the original to become jammed or damaged.

Also, when the top surface of the support plate is higher than the top surface of the sensor unit at the end of the sensor unit, the leading edge of the document will hit the step between the support plate and the sensor unit, causing a similar problem. surface and strong pressure (for example, in the case of an A4 manuscript, 1 kg/aJ at each longitudinal end)
More pressure is applied. ) while moving on the surface of the sensor unit, a considerable force is applied to the sensor unit in the direction of movement of the document. Even with strong adhesive, if used repeatedly, the sensor unit may separate from the support plate. Sometimes it peeled off or shifted.

[Problems to be Solved by the Invention] It is an object of the present invention to solve the above-mentioned problems in the prior art, to be able to convey a document well when reading an image of the document, and to
It is an object of the present invention to provide a fully contact type 1-magnification image sensor that can securely hold a sensor part on a support plate.

[Structure and operation of the invention]

The fully contact type 1-magnification image sensor of the present invention is a fully contact type 1-magnification image sensor in which a sensor portion having a photoelectric conversion element on a light-transmitting substrate is held on a support plate. (In the figure, 1 is the support plate, 2 is the sensor part, 3 is the translucent substrate, 4 is the photoelectric conversion element, and 5 is the manuscript) ,
The angle of the support plate with respect to the vertical direction, t is the depth on the upstream side in the document conveyance direction, t' is the depth on the downstream side, and Q is the width, and 0°<θ<90°, tanθ≦t/ There is a relationship of Ω. ), and a sensor portion having a thickness d (where d≦t) is fitted and held in this groove.

A feature of the complete contact type image sensor of the present invention is that a groove for holding the sensor portion is formed in the support plate. The first important thing here is that the depth t of the groove on the upstream side with respect to the document conveyance direction is greater than the thickness d of the sensor section.

If such a relationship exists, there will be no step between the support plate and the sensor section that would impede the flow of the document when the document is conveyed.

The second important thing is that when each side of the groove is oriented in the direction of gravity, the angle θ of each side with respect to the vertical direction of the support plate (also the inclination angle of the support plate with respect to the direction of gravity) is 0″<θ<
It is within a range of 90°. The effects of this angle limitation can be broadly classified into two types. One is that the area indicated by D in Figure 1 can be used as a guide for the document, and the other is that it works advantageously for the light guide holes provided in the support plate, as will be described later, to create a completely close-contact image. It is possible to improve the efficiency of light utilization for the sensor.

For example, if the support plate 1 is held at an angle of θ° in the direction of gravity as shown in FIG. 2, the conveyed document 5 will be conveyed along area D by its own weight.

This results in smooth contact with the surface of the sensor section 2.

The third important thing is that the relationship among the inclination angle θ, the groove depth t on the upstream side, and the groove width Ω satisfies the expression tan θ≦t/l. If this condition is satisfied, the depth t' of the groove on the downstream side will always exceed zero, and the groove can be used as a groove for holding the sensor section. Further, if the above formula is satisfied, peeling or slipping of the sensor portion from the support plate during repeated use due to the pressing force and rotational force of the backup roller can be prevented without using a strong adhesive.

In particular, according to experiments conducted by the present inventors, it has been found that the above-mentioned prevention effect is further improved when t'≧d/3. Also, the relationship between θ, t, Q and d in this case is ta
It has also been found that nθ≦t/ld/:3Q.

Next, the effect of improving light utilization efficiency in the image sensor of the present invention will be explained.

Not limited to the present invention, but in general full contact image sensors, the image of the original can be read by inputting light from the transparent substrate side, irradiating the original with the light, and applying the reflected light to the photoelectric conversion element. It is done. For this purpose, it is necessary to make holes for light guide in the support plate as well. In addition, in order to prevent stray light in general fully contact image sensors, a window is provided in or near the photoelectric conversion element to let in light, and a light-blocking layer is provided in other parts, and in order to prevent wear on the sensor part. 1
Providing a wear-resistant layer on the surface is practiced. According to experiments conducted by the present inventors, when the lighting window is located near the photoelectric conversion element, the light enters the lighting window in the perpendicular direction, as shown in Fig. 3 (7 is the lighting window, 8 is the light shielding layer, 9 is the light shielding layer, (surface wear-resistant layer), illumination efficiency is better when the light enters from an oblique direction.
This incident angle φ is 1 for both the photoelectric conversion element 4 and the lighting window 7.
It has been found that when the square is 00 μm×100 μm and the distance between its ends is 10 μ−, φ is preferably 10×45@. Note that in the present invention, the sensor section and the support plate are not parallel.

Because it has a certain inclination angle θ, it becomes a support plate.

If a light guide hole is opened in the vertical direction to this support plate, the incident angle φ becomes equal to the inclination angle θ. Therefore, by considering the illumination efficiency within a range that satisfies the above relational expression and selecting an appropriate θ, it is possible to improve the conveyance of the original, improve the retention of the sensor section on the support plate, and achieve the best illumination efficiency. , that is, it is possible to obtain light utilization efficiency.

For the above reasons, the complete contact type image sensor of the present invention has a structure in which the center line of the light guide hole 10 formed through the support plate 1 is perpendicular to the support plate 1, and the sensor A structure in which the light passes through the daylight window 7 of the section 2 is preferable.

The materials used for the complete contact type image sensor of the present invention may be exactly the same as conventional ones.

That is, a metal plate such as AQ is used as a support plate for holding the sensor section.

The translucent substrate that makes up the sensor section is blue plate glass,
A glass plate such as Pyrex glass or quartz glass, or a transparent resin film such as polyethylene or polypropylene is used.

Metals such as Cr, Mo, and Ti are used as materials for the light shielding layer.

The photoelectric conversion element is constructed using an a-8i (amorphous Si) semiconductor as a photoelectric conversion layer.

The surface wear-resistant layer is usually composed of thin glass such as Pyrex glass or quartz glass.

Additionally, in the present invention, a driving circuit including a thin film transistor (TPT) is added to drive the sensor unit.

The present invention will be explained below by way of examples.

Example As shown in FIG. 5, a quartz substrate 2 with a thickness of 1 m and a width of 3 mm was used.
A Cr thin film 8 for a light-shielding layer with a thickness of μm is formed on top of the Cr thin film 8 for a light-shielding layer, and on top of that a drive circuit 11 consisting of TPT with pofiy-Si as an active layer and an a-5i-based photoelectric conversion element (the size of each element 4 is 100 μm x 100 μm), and furthermore, after forming a lighting window 7 of the same size as the photoelectric conversion element 4 at a distance of 10 μm on the opposite side from the drive circuit 11 of each photoelectric conversion element 4, a surface wear-resistant layer is applied to the entire surface. (not shown) thickness 50μ-
The sensor part was created by gluing thin glass sheets together using epoxy adhesive.

Next, the surface of the AQ plate was processed as a support plate, and as shown in Fig. 1, t = 1.5 + m +, t' = 0.5 m, fl
=3.1m.

After forming a groove of θ=17.8” and fixing the sensor part therein using epoxy adhesive, the center line of the light guiding hole IO is aligned with the AΩ support plate as shown in Fig. 4. 0 in the direction perpendicular to the Q support plate 1 and passing through the center of the lighting window 7.
．． By forming a light guide hole 10 with a width of 8 m, a fully contact type 1x image sensor was created.

When a 20 mm diameter backup roller was installed on top of this image sensor and the original image was repeatedly read using an LED as a light source, good image reading was achieved without any jamming of the original or misalignment of the sensor when the original was transported. It was possible.

[Function and effect of the invention]

The fully contact type 1-magnification image sensor of the present invention uses a support plate provided with grooves that satisfy the above-mentioned relational expression, so when reading the original image, the original can always be conveyed well, and the original can be reliably conveyed. The sensor section can be held on the support plate. In addition, if the light guide hole of the support plate is formed so that its center line is perpendicular to the support plate and passes through the center of the lighting window, the best illumination efficiency can be obtained, and the light utilization efficiency can be further improved. can.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the dimensions and shape of the groove of the support plate used in the fully contact type 1:1 image sensor of the present invention, and FIG. 2 is an explanatory diagram of the conventional fully contact type 1:1 image sensor. FIG. 3 is an explanatory diagram of the angle of incident light on the sensor section used in the image sensor of the present invention, FIG. 4 is a preferred example of the image sensor of the present invention, and FIG. 5 is a sensor section prepared in the example. It is an explanatory view about the size and shape of. 1...Support plate 2...Sensor part 3...
Transparent substrate 4...Photoelectric conversion element 5...Original 6...Backup roll 7...Lighting window 8...Light blocking layer 9...Surface abrasion resistant layer 10...Light guide hole 11・
...Drive circuit patent applicant Rico Co., Ltd. - Figure 2

Claims (1)

[Claims] 1. In a fully contact type 1-magnification image sensor in which a sensor section having a photoelectric conversion element on a transparent substrate is held on a support plate, the support plate is shown in Fig. 1 (1 in the figure is the support plate, 2 is the sensor). 3, 3 is a translucent substrate, 4 is a photoelectric conversion element, and 5 is a manuscript). The depth on the upstream side in the conveyance direction of the document, t' is the depth on the downstream side, l is the width, and 0°<θ<90°, tanθ≦t
There is a relationship of /l. ), and a sensor portion having a thickness d (where d≦t) is fitted and held in this groove.